FORT MYERS, Fla. — From all indications, the Minnesota Twins have taken the right steps in managing star first baseman Justin Morneau's concussion, pulling him out of action right away, sticking to the advice of experts on the field and not pressuring him to return.

And yet, more than eight months after Morneau suffered the injury July 7, there's no certainty he'll be ready for opening day, let alone get back to his former MVP form.

For players, teams and fans, that unpredictability in the recovery time represents the most frustrating aspect of concussions, brain injuries that remain enigmatic despite significant medical advances.

No two concussions are alike, and they can range from the mild type that clears up in a few days, like the one Boston Red Sox pitcher Josh Beckett incurred when hit by an errant ball in practice Feb. 28, to the career-threatening ones.

"You see a guy miss a week with a concussion, and you see a guy miss a year with a concussion," says Morneau, 29. "When I got hurt, I didn't think I was going to be out that long. I didn't think it was going to be that bad."

Though they're much more prevalent in football and hockey, where they have become the subject of considerable debate and consternation, concussions also have left a mark on baseball.

Eight major league players went on the disabled list with concussions last season — Morneau and New York Mets outfielder Jason Bay being the most prominent — and 30 in the last six years.

Catcher Mike Matheny, a four-time Gold Glove winner whose case first raised awareness about the injury in baseball, and nine-year major leaguer Corey Koskie had to retire when they couldn't sufficiently recover from their 2006 concussions.

Major League Baseball and players association officials are working on implementing a seven-day DL for concussions, which union head Michael Weiner said could be in place when the season starts March 31, as well as protocols for returning players to action.

Those are among several proactive measures the game has taken in addressing the issue. MLB also started requiring in 2009 that all players have cognitive baseline tests — the results are compared with how a player does in the test after a head injury — and it has expanded the education of athletic trainers on the symptoms and treatment of concussions.

"Baseball has been excellent in providing that culture and that support," says University of Pittsburgh Medical Center clinician Micky Collins, one of the nation's foremost authorities on sports-related concussions. "If a team gives an athlete the support it needs to get better from this, man, does it go better. It's such an important part of this."

Morneau is the first one to say the Twins have been unflinching in their support, even though the 2006 American League MVP missed the second half of last season and could not help the club as it got swept by the New York Yankees in the division series.

For a while Morneau thought he would be able to return for the stretch run, but he could not shake the fogginess that afflicted him since his head collided with the knee of Toronto Blue Jays second baseman John McDonald while trying to break up a double play.

While his condition improved gradually over the offseason, Morneau had occasional recurrences early in the spring and did not make his Grapefruit League debut until March 11.

He has no hits in 10 at-bats, typically meaningless numbers for a player of his stature. Still, there's no clear sign the defending AL Central champion Twins can pencil him in for his usual 30 home runs and 100-plus RBI, or even count on him daily.

"We have the data from before as far as reaction times — the concussion test we do (known as ImPACT) — and the reaction time and everything else is back to normal," Morneau says. "Now it's going to take the reps to feel the data is right and you can be the same player."

ImPACT, which Collins helped develop, is a computerized cognitive test that assesses concussions.

Bay, 32, a three-time All-Star, has been symptom-free all spring and is batting .333 in 39 at-bats. His whiplash-induced concussion, suffered when he crashed into a Dodger Stadium fence July 23, seemed mild enough that he played in the next two games.

Shortly afterward, he reported a persistent headache that became his companion 24 hours a day for the next month and forced him out of the lineup for the rest of the season.

Bay found the treatment for his concussion — rest and relaxation — almost as difficult to handle as the injury.

As an athlete, he was used to frequent activity, and the lack of it — combined with the symptoms from the concussion — made him miserable.

"When you're not doing anything else, thinking about your concussion occupies all your time," Bay says. "You can watch TV if you can tolerate it, and early on I couldn't. … Or (you can) read a book with the iPad or use the computer or nothing. … That was the toughest part: Do nothing, but do something to keep your mind off it. Well, what is that?"

Players on the DL for extended stretches often feel isolated because they can't contribute. That sensation is even more pronounced for those with concussions, because few teammates have been through them.

The Twins had not had a concussion since Morneau got beaned in 2005, forcing him to miss 13 games, and he describes the feeling as being alone on an island.

Minnesota center fielder Denard Span can relate, having endured an inner-ear infection in 2008 that made him dizzy, and the two shared their stories.

"With a head injury like that, you can't see any physical signs," Span says. "We don't see a scar; we don't see a cast or an incision. So it's tough mentally."

Morneau also found comfort and guidance in Koskie, his teammate in 2003 and '04. Koskie advised Morneau to be honest with doctors and not try to rush back. Koskie got hurt July 5, 2006, on a seemingly harmless play when he hit the ground awkwardly while chasing a pop fly. He tried to return less than 10 days later while not fully recovered.

"My symptoms went from a 2 or 3 to like a 9," Koskie says. "After I tried to push myself, the next day I woke up and my head felt like my brain was trying to crawl out of my skull. I was really dizzy, really nauseated. I couldn't focus. I couldn't go on the computer. I couldn't watch TV. I got numbness on one side of my body. It just wasn't good."

Morneau, Bay and Koskie grew up in Canada playing hockey, which exposed them to head blows and possible concussions as youths that might have gone untreated, though Bay dismisses that connection because he stopped playing hockey at 13.

Collins says concussed athletes are vulnerable to more harmful consequences if hit in the head again before the brain has recovered. But, he adds, once the injury has healed, his experience shows they are at no greater risk than before unless they have an innate predisposition. "I know everyone thinks one plus three equals 10 with this injury," he says. "I don't feel that's necessarily the case."

Among the many advances in recent years, medical researchers are starting to identify which symptoms predict a worse outcome, and they're also devising treatment methods that include physical therapy and medication.

Fogginess, Morneau's chief symptom, ranks high among the indicators of a longer recovery time, along with dizziness and reaction-time problems.

Now that his head is clear, Morneau is protecting it by wearing a helmet during batting practice, albeit one without an earflap. He switches to the earflap-equipped Rawlings S100P batting helmet for games. He still wears a cap in the field.

"I would recommend to everyone to switch to this helmet even if it looks a little goofy," Morneau says. "You don't really want to go through this."